Lifting-jack.



PATENTED NOV. 7, 1905.

C. E. ROTH.

LIPTING JACK.

' APPLICATION FILED nomzs, 1903. RENEWED AUG. 4,1905.

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WITNESSES.-

UNITED STATES CHARLES E. ROTH, OF NEW YORK, N. Y.

LlFTlNG-JACK.

Specification of Letters Patent.

Patented Nov. 7., 1905.

Application filed November 23, 1903. Renewed August 4, 1905. Serial No.272,795.

To all whom it may concern.-

Be it known that I, CHARLES E. ROTH, a citizen of the United States,residing at New York city, State of New York, have invented new anduseful Improvements in Lifting- Jacks, of which the following is aspecification.

My invention relates to lifting-jacks of that type in which alifting-screw is operated by means of a gear-wheel and worm.

One of the principal objects of the invention is to provide a device ofthis character which shall be simple in construction and of few parts,which will not readily get out of order, and which may be quickly takenapart for repairs or to replace worn or defective parts, and which maybe readily reassembled without special tools.

Another object is to provide a strong and durable device of thecharacter referred to and one in which the lifting-screw shall be firmlymounted in a true vertical position to avoid torsional strains on thevarious parts of the structure.

A further object is to provide simple and efficient means for coveringor housing the operative parts of the jack in order that dirt, grit, orany foreign substance may not find ready entrance to the working partsto interfere with the smooth and easy operation of the mechanism. I havealso provided a cover or housing for the operative mechanism which canbe readily removed in order that access may be had to said mechanism forthe purpose of replacing worn or broken parts and for lubricating thebearings when found necessary.

The objects referred to are attained by means of the constructionillustrated in the accompanying drawings, in which Figure 1 is a view invertical section of a lifting-jack made in accordance with my invention.Fig. 2 is a top plan view and partial section of the same with the capor cover of the housing removed to better illustrate the interiormechanism.

In order that the parts subjected to the greatest strains in use mayhave the required strength, I have given such relative proportions tothe different parts as will secure practical uniformity when constructedof the materials and of the relative dimensions set forth andhereinafter disclosed.

Referring to the accompanying drawings for a more particular descriptionof my invention, the numeral 1 designates the body or standard of thejack. This body or standard is preferably made of cast-iron, the lowerportion or base 2 being enlarged to provide a firm support for the ackand the body portion of the standard being hollow, as shown. The upperportion of the body is enlarged, as at 3, to provide a housing for thegear-wheel and worm. A shouldered recess 4 is formed in the body andsupported within this recess is the annular ball-bearing ring or raceway5, the upper surface of said ring having, preferably, two annulargrooves 6, which. provide raceways for the steel balls 7. The gear-wheel8 may be of case-hardened cast-iron and is provided with a dependingbushing or boss 9, which fits smoothly within the upper portion of thestandard to insure a true vertical alinement of the lifting screw. Ashoulder 10 is formed on the gear-wheel below the cogs or threads 11,and firmly seated against said shoulder is a bearing-ring 12, whichpreferably has a smooth under face to rest upon. the steel balls 7. The'bearingrings 5 and 12 maybe secured in place by shrinking orotherwise. The bearing-ring 5 is preferably so constructed and attachedwithin the body portion of the jack as to be readily removable and to bereplaced when desired, while the bearing ring 12 is preferably shrunk orswaged against the laterally-extended shoulder 10 of the gear wheel. Aboss 13 is formed upon the upper end of the gearwheel, and this bossfits within an opening 14 in the removable cap or cover 15. A shoulder16 is provided immediately above the threaded portion of the gear-wheel,and the cap or cover 15 rests upon this shoulder.

It will be noted that the bushing 9 and the boss 13 may be ofsubstantially uniform diameter and that the shoulders 10 and 16 arepreferably of substantially equal area, the object being to attain thegreatest possible strength in line with the lifting screw by equalizingthe bearing area of the gear wheelby requisite proportions. Further,said shoulder 16 also constitutes an extended bearing-surface wherebythe gear-wheel is prevented from moving upward from any cause, Thecrucible-steel lifting-screw 17 has a comparatively long screw-threadedbearing within the gear-wheel, owing to the extended bushing 9 and theboss 13, and is thus firmly seated in a true vertical line relatively tothe body or support. This is a matter of considerable importance in adevice of this character, as any torsional or sidewise strain would havea tendency to injure or crush some of the parts under the great weightbeing raised. The head 18 rests upon the upper end 18 of thelifting-screw 17, a set screw or pin 19 being used to hold the top 18 inplace. The crucible-steel worm 20 has one end 21 of its shaft j ournaledin a boss or enlargement 22, formed inside the body 1, and the otherbearing for the worm-shaft is formed in a steel bushing 23, and saidbushing is fitted into a threaded enlargement 24, formed inside thebody 1. A pinor screw 25 holds the bushing 23 in place in its bearing. Ahandle 26, Which-may be of the ratchet type, is secured in any suitablemanner to the outer end of the worm-shaft. The top or cover 15 may beheld in place by screws which pass through said top or cover and intothe holes 27, formed in the top of the body portion.

It will be noted that when the head 18 is secured in place upon the end18 of the lifting-screw 17 the flat lower end of the head 18 extendsbeyond the shoulder 14 on the gearwheel 8 and covers the joint betweenthe boss 13 and the opening in the top of the coverplate 15, and thusserves to keep grit or dirt from gaining access to the working parts ofthe jack when not in use.

From the foregoing it will be obvious that my liftingjack iscomparatively simple in construction, is composed of few parts, that theoperative mechanism is completely covered and housed in to protect itfrom injury, and that access may be readily gained to the parts forrepairs, that the lifting-screw is seated in a long bearing to hold itin vertical position to prevent sidewise strains, and that the relativeproportions of the parts are such as to secure substantially uniformstrength to the ack in its various parts.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is

1. A lifting-j ack comprising a hollow body portion, a gear-wheel havinga bushing depending from one end thereof and a boss extending from theopposite end thereof, said bushing being seated in a bearing in the bodyportion, a ball-bearing for the gear-wheel, a threaded lifting-screwpassing through the gear-wheel and bushing, and a removable cover-platefor inclosing the operative parts of the jack, said cover-plate havingan open- 5 5 ing through which the said boss extends, and the upperfaces of said boss and plate being flush.

2. A lifting-jack comprising a hollow body portion, provided with aninterior shoul- 6o dered recess, a ball-raceway in the form of a ringseated in the recess and provided with ball-grooves, balls in thegrooves, a smooth-' surfaced bearing-ring resting upon the balls,

a gear-wheel resting upon the bearing-ring, a

bushing extending from the gear-wheel and seated in a bearing in thebody, a boss ex tending from the upper end of the bushing, alifting-screw, a worm for revolving the gearwheel and lifting the screw,and a removable 7o raceways, a gear-wheel provided with a dependingbushing journaled in the hollow body portion, a bearing-ring secured toa shoulder on the gear-wheel and resting upon the balls, a worm-shaftjournaled at one end in the body portion, a threaded bushing in whichthe opposite endof the worm-shaft is journaled, and a removablecover-plate for covering the operative portions of the jack, saidcover-plate having an opening which fits over a boss on the upper end ofthe bushing and the plate and boss having flush upper surfaces.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES E. ROTH.

Witnesses:

Jos. I-I. BLAOKWOOD, E. P. BUNYEA.

